1. Field of the Invention
The present invention relates to cryogenic storage containers that must withstand extreme temperature and pressure conditions (such as minus four hundred fifty degrees Fahrenheit and/or high pressure in excess of ten thousand p.s.i.). Even more particularly, the present invention relates to a storage container with a composite laminate structural, load bearing wall that is lined with a film laminate. The film laminate preferably includes at least two metalized film layers bonded with an adhesive so that the metalized surfaces of the film layers abut.
2. General Background
A primary application for cryogenic or high pressure tanks is in the space industry. Cryogenic or high pressure tanks are used on launch vehicles and satellites. In any space vehicle, launch vehicle or the like, reduced weight is of utmost importance. This need for a lightweight cryogenic or high pressure tank applies to primary launch vehicles, upper stage launch vehicles and/or orbit maneuvering vehicles.
There are a number of cryogenic tank and composite tank constructions that have been the subject of patents. A recent patent, U.S. Pat. No. 5,005,362 entitled "Cryogenic Storage Container" issued to William R. Weltmer, Jr. et al. The Weltmer '362 patent provides a cryogenic storage container having a pressure vessel surrounded by a vacuum vessel for maintaining a vacuum between the outer wall of the vacuum vessel and the pressure vessel. A pair of intermediate and sub-intermediate heat shields are disposed between the outer wall of the vacuum vessel and the pressure vessel for intercepting the heat that would otherwise be transferred from the vacuum vessel to the pressure vessel. The heat intercepted by the intermediate heat shield is absorbed by liquid nitrogen contained within a liquid nitrogen container. The heat intercepted by the sub-intermediate heat shield is preferably absorbed by liquid neon in a liquid neon storage tank. The liquid nitrogen and neon absorb heat by undergoing a phase change, from liquid to vapor. In order to prevent failure of the liquid nitrogen container, the nitrogen is vented to the atmosphere over a period of time. The vaporized neon, on the other hand, flows into an absorbent canister containing activated charcoal to absorb gaseous neon for regeneration back to liquid neon at a future time.
U.S. Pat. No. 4,507,941 entitled "Solid Subliming Cooler With Radiatively-Cooled Vent Line" discloses the vent line of a space-borne solid subliming cooler formed to provide a heat radiator which radiates much of the heat losses otherwise parasitically conducted back to the cooler, thereby permitting the use of certain high heat capacity cryogens at operating and working temperatures requiring very low operating vapor pressures but without as much parasitic heat conduction loss as is associated with conventionally vented solid subliming coolers.
The Zwick U.S. Pat. No. 4,472,946 provides a cryogenic storage tank with a built-in pump for pumping cryogen directly from the primary storage container consistent with low boil-off losses of cryogen having a outer vessel, an inner vessel and an evacuated insulation space therebetween. A pump mounting tube assembly extends into the interior of the inner vessel and includes an inner pump mounting tube and an outer pump mounting tube joined at their lower rims to define an insulating jacket between the two tubes. The inner pump mounting tube is affixed at its upper end to the outer vessel while the outer pump mounting tube is affixed at its upper end to the inner vessel. The inner pump mounting tube defines a relatively long heat path into the cryogenic container and is itself insulated from the liquid cryogen by a pocket of trapped gas formed within the inner pump mounting tube by heated cryogen. A pump may be introduced through the inner pump mounting tube and is also insulated against contact with liquid cryogen by the trapped gas such that only the lowermost end of the pump is immersed in cryogen thereby minimizing heat leakage into the tank.
The Argy U.S. Pat. No. 4,461,398 provides a storage tank for cryogenic liquefied gases comprising an outer shell, a fluid-tight inner shell defining the storage space containing the liquified gas and an insulating structure provided in the evacuated intermediate space, the insulating structure including a wall made of juxtaposed hollow, evacuated panels, the joints between adjacent panels being tightly covered by elements adapted to take up the cold-induced wall shrinkage, the elements and the inner wall of said juxtaposed panels forming said inner shell.
The Kotcharian U.S. Pat. No. 4,366,917 discloses a cryogenic tank comprising an innermost fluid-confining wall forming a primary barrier made from relatively thin, flexible, impervious, sheet-like laminated building material comprising at least three continuous overlying layers of yielding material adapted to withstand very severe cold conditions, bonded together and consisting of at least one first mechanically strong supporting outer layer, at least one impervious film-like intermediate layer and at least one second inner lining layer providing at least a mechanical and at least temporary protection.
U.S. Pat. No. 4,101,045 issued to Roberts et al. discloses a cryogenic container adapted to store or transport liquified gases, the container including an outer tank formed by walls which have thermal insulation properties and are structurally capable of supporting the load, the walls incorporating a liquid and gas-impervious secondary barrier. Received within the outer tank and readily removable therefrom is a prefabricated independent inner tank constituted by a flexible bladder whose geometry roughly conforms to the contours of the inner surface of the outer tank. The bladder is formed of a synthetic plastic fabric material that is coated to render it liquid and gas-impervious to define a primary barrier, which coated fabric material maintains its flexibility and other physical characteristics at cryogenic temperatures and has sufficient structural strength to sustain the cryogenic liquid load without any danger of rupture even in those areas thereof in which the bladder does not fully conform to the contour of the outer tank surface and is not backed thereby. The Robert '045 patent discusses previous forms of cryogenic containers that proposed employing an inner liner of Mylar, fiberglass or other non-metallic material as a primary barrier.
The Whillock et al. U.S. Pat. No. 3,972,467 provides an improved paper-board laminate for containers for bulk packaging liquids, syrups and pastes which includes a layer of a high strength polymer film and which may also include a layer of aluminum foil.
The Borup U.S. Pat. No. 3,929,247 discloses an internally insulated tank for the transportation and storage of cryogenic liquids, such as liquified natural gas. The inner surfaces of the tank are lined with rigid, closed cell polyurethane foam to which is bonded a thin impervious sheet material, such as aluminum foil.
The Smith et al. U.S. Pat. No. 3,795,573 disclosed a liner for a cryogenic tank that comprises multiple layers of woven polyester fibers such as woven polyethylene terephthalate fibers and stress-oriented polyethylene terephthalate films (MYLAR), and aluminum. The preferred liner comprises two layers of aluminum positioned side by side to provide liquid-vapor permeability. One of the aluminum layers is approximately one mil thick, the other being about one half mil thick. Two layers of polyethylene terephthalate film are positioned on opposite sides of the two layers of aluminum. Each of the film layers is about one half mil thick.
The Sterrett U.S. Pat. No. 3,760,971 discloses a container for cryogenic fluids wherein a first layer of insulating blocks completely lines the interior of the container and at least a portion of one face of each block is bonded to the interior of the container by a cryogenic adhesive. The sides of the insulating blocks have a contractible insulating material completely surrounding them. At least a second layer of insulating blocks is bonded to the first layer of blocks; at least about two percent of the areas common to the faces of the first and second layers of blocks are bonded. The sides of the second layer of blocks are surrounded by a contractible insulating material. The face areas common to the blocks that are not bonded preferably have a substantially non-friction material attached thereto. The layers of blocks are arranged so that there are no direct: heat paths to the walls of the container. A membrane of Mylar polyester film completely covers the interior of the container and is sufficiently bonded to the interior layer of blocks to support the Mylar film. Optionally, another layer of insulating blocks can be bonded to the Mylar film and then another layer of Mylar film bonded to this layer of blocks. This is preferred for containers used in transporting cryogen. Where the container is stationary, the top of the container does not have to have the membrane of Mylar film.
The Slysh et al. U.S. Pat. No. 3,713,560 discloses a spaced wall container having an inner wall for containment of fuels, cryogenic liquids, and the like spaced from and connected to, an outer structure by a plurality of tension members to create steady-state stabilizing forces on the outer structure by utilization of the radial and tangential stiffness of the pressurized inner wall. The tension members are spring-biased to ensure tension loading under all conditions. Insulation material is mounted on the tension members between the inner wall and outer structure. Protection against fluid leakage into the insulation material is afforded by a shield interposed between the inner wall and the insulation. The outer structure forms a protective enclosure for the inner wall container in addition to forming the external wall of a Dewar flask when the void between the spaced walls is evacuated.
The Hornbeck U.S. Pat. No. 3,692,206 discloses a system for suspending the inner vessel of multi-walled containers such as used for storing cryogenic fluids. The suspension system is characterized in that elongate members are used to hold the inner vessel in pure tension so that the inner vessel can expand or contract without changing the load on any of the support members, There is also provided locking means to rigidly secure the inner vessel from movement during transport of the container.
The Trenner U.S. Pat. No. 3,655,086 discloses a receptacle for storage of liquified gases at cryogenic temperatures. The disclosed tanks comprise two concentric shells with dished ends. The internal shell is fabricated from layers of glass fabric with organosiloxane treatment. A layer of high tensile wire fabric is incorporated as one of the integral laminae of the internal and external shells. The internal shell is covered with an insulating layer of flexible and rigid urethane foam. This foam is fabricated in contoured or flat blocks of suitable size and shape to conform to the inner shell. The blocks may be separated from the inner shell by multiple layers of metalized polyethylene terephthalate (Mylar), or other material which will reflect radiant heat.
A liner system for retaining liquid in a storage tank is the subject of U.S. Pat. No. 3,558,000. The liner system includes a continuous metallic liner which has sides which are substantially coextensive with the sidewalls of the tank and a bottom which is substantially coextensive with the floor of the tank. Upright expansion joints, provided in the sides of the liner, compensate for expansion and contraction of the sides in a circumferential direction and expansion joints, provided in the bottom of the liner, compensate for expansion and contraction in the bottom of the liner. Hanger members are secured to the upper portion of the tank and are resiliently mounted thereto. The upper end of the sides of the liner engage the resiliently mounted hangers so as to compensate for expansion and contraction of the liner in a vertical direction.
U.S. Pat. No. 3,410,443 entitled "Thermally Insulating Filler" provides a rigid thermally insulating filler bodies composed of aluminum foil laminated to rectangular plastically deformable thermally insulating synthetic-resin foil, opposite ends of the rectangle being bent toward one another to impart a generally cylindrical tubular configuration to the body. The body is open at its opposite axial extremities, while the ends of the rectangle, which are turned toward one another, do not overlap and define a gap between them along a generatrix of the body.
The Mearns et al. U.S. Pat. No. 3,101,861 discloses a vessel for transporting low temperature liquids. The '861 patent is concerned with and adapted for installation in marine vessels wherein a first outer tank shell of rigid and most likely metallic material is provided with a plastic insulating material lining the interior of the tank shell and preferably sprayed in place with an incorporated expanding or foaming medium of suitable kind. The inner surface of the outer tank shell, whether the shell be of metal, plastic, or other material, can be sprayed with a suitable primer before application of the foamed plastic insulation thereunto to prevent oxidation thereof and improve adhesion of the foam.